Known in the art is a corrugated structure comprised of triangular or rectangular corrugations defining parallelly arranged passages for a heat-transfer agent to flow therethrough. Located at the side surfaces of the corrugations to conform to the path of travel of the heat-transfer agent are continuous successive transverse projections and recesses adapted to define in the passage continuously and successively arranged divergent-convergent portions, the edges of the projections and recesses having stream-lined or rounded off configuration. The side surfaces of corrugations running in parallel with the path of the heat-transfer agent can be further provided with adjacent pairs of the transverse projections and indentations separated along the path of travel of the heat-transfer agent by flat or smooth portions, thereby forming successively alternating smooth and divergent-convergent passages, the projections and recesses extending either across the entire height of the ridges of the corrugations or, alternatively, occupying only part of the height thereof. As a result of constructing or throttling of the flow of the heat-transfer agent, three-dimensional core eddies are induced along the walls of the convergent portion of the passage. Eddy viscosity and conductivity tend to grow in the wall boundary area of the heat-transfer agent stream, which gives rise to an increase in the thermal gradient and density of the heat flow resulting in an improved heat transfer coefficient between the heat-transfer agent and the side walls of the corrugated plate.
However, under certain conditions of the heat-transfer agent flow and at certain dimensions of the projections and recesses power-intensive eddies tend to form in the divergent portion of the passage caused to interact with the flow core as a result of their diffusion thereinto. This entails an increase in the total energy expended for force drafting the heat-transfer agent with practically no improvement in heat transfer between the flow and the side surfaces of the corrugated plate. A similar interaction with the flow core occurs if an eddy formed in the divergent portion of the passage comes across a successive projection to diffuse into the flow core in a construction of a corrugated core structure with continuously arranged transverse projections and recesses separated successively by smooth portions of the walls of the corrugations. Thermohydraulic efficiency of the corrugated core structure of such a design is still low. Insufficient use is made of intensified heat exchange by successive throttling the flow of heat-transfer agent also in the case when the eddy induced in the divergent portion of the passage completely dissipates its energy at the smooth portion of the passage, which is accompanied by restored laminated structure of the boundary layer in the flow of the heat-transfer agent.